The semantic caching can efficiently support the applications in the context of mobile computing.Most existing algorithms for query trimming suffer high time and space complexity and they can't be used in small mobile devices.To this end

we propose 20 rules and a dynamic semantic merging strategy to simplify the complexity of query trimming

which is measured by the numbers of predicates that are depicted in the description for the semantic cache or queries.Some experiments on Android system show that disjunction simplification algorithm along with Completive Merging strategy can get the best performance for simple queries among the alternatives.For complex queries

the dynamic merging strategy based on predicate simplification can balance the complexity between caches and query processing and gain a good performance in a wide range.